Apparatus for developing photographic films



May 14, 1957 M. SHAPIRO 2,791,951

APPARATUS FOR DEVELOPING PHOTOGRAPHIC FILMS Filed May 17, 1955 5 Sheets-Sheet 1 Y y 14, 9 M. SHAPIRO 2,791,951

APPARATUS FOR DEVELOPING PHOTOGRAPHIC FILMS Filed May 17, 1955 5 Sheets-Sheet 2 K, Q N

\2 Q N w g I @5 s I n I I "dv s INVENTOR. MITCHELL SHAP/RO BY %W y 14, 11957 M. SHAPIRO 2,791,951

APPARATUS FOR DEVELOPING PHOTOGRAPHIC FILMS Filed May 17, 1955 5 Shee'ts-Sheet 3 INVENTOR. Fig. 4 MITCHELL SHAP/PO APPARATUS FOR DEVELOPING PHUTO- GRAPHIC FILMS Mitchell Shapiro, Pittsfield, Mass.

Application May 17, 1955, Serial No. 508,855

2 Claims. (CI. 95-93) This invention relates to improvements in developing apparatus for developing photographic films and has for one of its objects to provide a tank wherein the developer and films may be agitated much more thoroughly than by present-day equipment.

By employing a tank of my improved construction I am enabled to agitate the developing material in a much more irregular manner than possible with prior constructions-the tank can be agitated in an irregular manner through 360-and I have found that this type of agitation produces much better results than possible with conventional equipment in that the films are uniformly developed and the production of striations and other objectionable markings or patterns encountered in the use of prior developing equipment is avoided.

In general, my invention provides a developing tank for the reception of a hanger rack and film hangers and the developing material. The tank is provided with a hermetically sealed cover and is mounted in suitable bearings so that it can be rotated through a full 360 and rocked back and forth or in other irregular manner, which, as above pointed out, produces excellent results so far as uniform development of the films is concerned.

Provision is made for operating the tank when only partially filled with film, my apparatus embodying a quick-action clamp for clamping the film hangers in place when the tank contains but a few films instead of being loaded to capacity.

In the accompanying drawings,

Fig. 1 is a part-sectional, side-elevational view of an embodiment of my invention;

Fig. 2 is a part-sectional, end-elevational view of the apparatus of Fig. 1;

Fig. 3 is an isometric view illustrating the hanger rack and a quick-action clamp for holding the hangers in place on the hanger rack when the tank is only partially filled; and

Fig. 4 is an isometric view of one of the film hangers.

Referring to the drawings in detail,

2 designates the tank of my invention. The tank is rectangular and at each end is provided with trunnions 4, which are removably journaled in open bearings 6 in or on the supporting stand 8. Each of the trunnions 4 projects beyond the bearings 6 and is engaged by a locking loop 14, carried by a locking lever 16, which is pivoted on the face of the stand 8. This construction provides for easy removal of the tank from its bearings and also makes provision for rotation of the tank through a full 360 turn or as many turns as may be found desirable.

To hold the tank 2 against rotation when loading and unloading film, I provide the stand 8 with a locking screw 18, which is adapted to be screwed into engagement with the side of the tank. I may use a pair of screws, as illustrated, or but a single screw.

The upper edge of the tank is provided with a sealing gasket 20, which is engaged by a tank cover 22. This cover is provided with an annular peripheral flange 24, overlapping the tank walls when the cover is in place.

atent The cover is clamped in place by quick-action clamps, each comprising a stud 26 integral with the cover flange 24, a cooperating clamping and locking loop 27, and locking and clamping lever 28, the latter being pivoted to the tank side. With the clamps closed, as illustrated, the cover 22 is drawn tightly against the gasket 20, so that the tank is hermetically sealed and can be rotated in its bearings Without spilling of the developing fluid from the tank.

Within the tank 2 I employ a hanger rack 30, removably supporting the film hangers 32, which carry the films which are to be developed. The hanger rack 30 is made of angle irons, and its outside dimensions are just slightly less than the interior of the tank 2 so that, while the rack fits the tank, it may readily be placed in or removed from the tank. To facilitate handling of the rack, it may be provided at each end, for example, with a handle, such as shown at 34 in Fig. 1. The film hangers 32 are simply rectangular frames, somewhat shorter than the transverse width of the tank 2, and the top bar 36 of these frames rests upon the top side rails 38 of the hanger rack 3 The upper edge of the tank 2 is bent outwardly, as shown at 40, along the two long sides of the tank, to accommodate the ends of the top bar 36 of the film hangers, which extend beyond the side members of the film hangers to provide handles 42 for handling the hangers without the necessity of disturbing the hanger rack.

it will be quite apparent from all of the foregoing that in use the tank of my improved apparatus may be rocked back and forth for a full turn or for a partial turn at the will of the operator so as to ensure that the films will be thoroughly and uniformly developed and so as to avoid striations and other undesirable markings or patterns on the face of the films.

Where the number of films to be developed is something less than the capacity of the tank 2, I employ a clamp for holding the film hangers in place. This clamp is illustrated in Fig. 3 and comprises a frame, preferably of metal, composed of side members 44, bottom members 46, top members 48, and a central member 50. The outer ends of the bottom and top members 46 and 48, respectively, are loosely pivoted to the lower and upper ends of the side members 44. The inner ends of the bottom and top members are loosely pivoted to the central member 50. The central member 50 is extended above the top members 48, and one of the side members 44 is similarly extended, and pivoted to the outer ends of these extensions is a lever or operating member 52. The fulcrum of this lever is at the pivotal connection of the lever with the outer end of the central member 50. This arrangement provides for lengthening and shortening of the clamp simply by depressing or elevating the free end of the lever 52.

in use, after the film hangers 32 have been suspended from the hanger rack and assuming the number of hangers is something less than the capacity of the hanger rack, the clamp of Fig. 3 is simply placed within the hanger rack beside the film hangers, and then the lever 52 is depressed to lengthen the clamp so that it will be jammed against the sides of the tank, the clamp being so dimensioned that the lever 52 and bottom and top members 46 and 48 will then be parallel to each other and the pivotal connection of the bottom members 46 to the side members 44 and central member 50 will be in line with each other, and the pivotal connection of the top members 48 to the side members 44 and central member 50 will be in line with each other, so that the clamp will remain extended until the lever 52 is raised again.

it is to be understood that changes may be made in the details of construction and arrangement of parts herein- Patented May14, 1957' above described without departing from the spirit and scope of my invention.

What I claim is:

1. Film-developing apparatus comprising, in combination, a tank; a hanger rack removably mounted within the tank for the suspension of film-supporting hangers within the tank; a hermetically sealed cover for the tank; a trunnion on the exterior of each end of the tank; a tanksupporting. frame; open hearings on said frame for said trunnions, to mount the tank for rotation through 360; clamps carried by the frame for holding the said trunnions in said bearings, the tank being removable from said bearings when the said clamps are opened; and a pin passing through said frame for engagement with the tank wall, to prevent rotations of the tank during removal and insertion of the hanger rack.

2. Film-developing apparatus comprising a tank; bearings for the tank in which the tank is removably and rotat- References Cited in the file' of this patent UNITED STATES PATENTS 771,358 Dorr Oct. 4, 1904 1,136,703 Neshime et al. Apr. 20, 1915 2,056,298 Schnelz Oct. 6, 1936 2,297,906 Mace Oct. 6, 1942 FOREIGN PATENTS 484,930 Italy Sept. 26, 1953 

